Control Arm Mercedes W211 W219 Wishbone Rear Suspension Left R2303521805

Mercedes W211 W219 Rear Left Suspension Control Arm R2303521805 is an original part from the Control Arms and Ball Joints group, designed for the rear left side of the suspension. Engineered by the vehicle manufacturer, it ensures proper axle geometry, stable vehicle handling, and predictable body behavior during braking and cornering.

Specifications and technical data

• SKU: A2303503506
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A2303503506
• Substitutable numbers: A2303503506, A 230 350 35 06, R2303521805, R 230 352 18 05
• Location on the vehicle: Rear, Left
• Category: Control Arms, Ball Joints & Assemblies

Intended Use and Function in Suspension

The presented control arm operates on the rear axle, left side, responsible for precisely maintaining the wheel's position relative to the body. A correctly chosen component in this area influences:

• maintaining correct toe and camber angles,
• straight-line stability at higher speeds,
• even tire wear and predictable suspension system responses.

Thanks to its construction aligned with the original Mercedes suspension design, the control arm works in conjunction with other system components, reducing unwanted play and improving ride comfort.

Benefits of Using an Original Control Arm

Using an original control arm in Mercedes E-Class and CLS models allows for the preservation of the manufacturer's intended driving characteristics. In practice, this means:

• consistent operation with other suspension components – shock absorbers, springs, and ball joints,
• appropriate stiffness and operating characteristics of the arm throughout its entire range of motion,
• reduced risk of incorrect geometry alignment after replacement.

A part from this group is particularly important when experiencing audible knocks from the rear of the vehicle, unstable handling, or problems with geometry alignment on the rear left axle.

Condition, Fitment, and Installation

The offered control arm is a used part, which allows for an economical repair while maintaining the original construction. This type of part is a good choice when the existing control arm has suffered mechanical damage, corrosion, or deformation after a collision.

Before installation, the standard workshop procedure is recommended: checking mounting points, verifying cooperating joints, and subsequently setting the rear axle geometry. A correctly installed control arm restores predictable vehicle behavior and improves ride comfort.

Technical Support and Suspension Component Selection

When working on the rear axle, it is advisable to treat the suspension system as a whole – especially in vehicles driven on poor road surfaces. Replacing a single control arm often involves checking other arms, bushings, and ball joints to avoid the recurrence of unwanted play and noises.

For users who want to better understand the relationships between individual suspension components, a guide describing the role of shock absorbers, control arms, and stabilizers in various models will be useful. A detailed discussion can be found in the article Suspension System – A Comprehensive Guide to Shock Absorbers, Control Arms, and Stabilizers, which also covers the topic of control arms in Mercedes E-Class models.

Expanding Repairs within the Same Group

If you are planning a comprehensive repair or upgrade of the rear axle suspension area in your Mercedes and need other parts from the same group, such as additional arms, ball joints, or mounting brackets, check the available parts in the Mercedes Control Arms and Ball Joints category.